Touch screen does not work

I replaced the original touch screen after ripping the digitizer ribbon when I opened my iPod Touch 2g for the first time to replace the battery. However, even with the new digitizer, the touch screen will not work, but the home button does. I wonder, do I need all the little screws screwed back in place behind the battery as well as in all other places? Or should I try and get another replacement digitizer as I've seen in other posts that said they had to make multiple tries from different vendors from ebay?